Dosing ALK questions

[homer1475]

So after several weeks of low ALK I decided to start dosing randys 2 part(just the alk part 2 1/4C of baked baking soda to 1G RO/DI) yes my PH is also low at 7.8 to 7.4 at night). My Calcium is 450 and mag is 1400, and alk is 7.2dkh so I only need the alk part right now. Several weeks of testing have come in right at 7.3.

I used the reef calculator and it said I needed 30ml to bring my alk up to 9dkh. I dosed this all at once which shot my PH up to 8.3 and my alk up to 9. Today I tested again and I'm down to 7.3 again. Is it possible to use that much alk in one day?

Anyways my question is, do i have to dose this every day? I was assuming since several weeks of testing have come in at 7.3 I would only need to dose this once in a while. Do I have to keep dosing it to maintain the 9dkh?

Assuming( I will test daily for a few days) that my alk is going to always go down to 7.3 in 24 hours, do I have to dose the 30ml every day? Is it best to dose ALK in a large dose or several small doses?

 

[Dkuhlmann]

I think most people are adding it to their top off water daily. Sk8r has a thread on adding Kalk (pickling lime) to the top off water.

 

[homer1475]

I tried that, raised my Kalk to high(490 at its peak) so I stopped.

I only need to raise my ALK. I know 7.3 isn't terrible, but 9 would be better.

 

[NS Mike D]

I dosed Kalk and my calcium went very high. I am now dosing baked baking soda. It raises alk without raising calc. but be careful as it also raises ph. Unbaked baking soda will do the same but lower ph. Use the online calculators and test to make sure you don't swing ph too quickly


My tank consumes carbonates faster that calcium, so I merely accept this. My water changes are sufficient to replenish calcium and Mg. So I supplement AK with baked baking soda.

I don't have much in the way of stony corals. I suspect if I did then my calcium consumption would increase and thus warranting switching to kalk. The first 8 moths of my tank required no dosing was the water changes was sufficient.

edit: My alk was fine until September when it started dropping. Got as low as 7.0 when I started dosing with kalk. Got it over 8 when my calcium shot up to 850 and started to precipitate as little white dots around the tank. I don't have the new numbers as I am a a half week past my weekly testing but since adding kalk and then baked baking soda, my corals are looking healthier and a number are multiplying. But that could also be that I am increased supplementing phytoplankton and zooplankton feeding to every three days.

 

[TangingOut]

You need to find your tank's daily usage of Alk. Do so by testing several consecutive days at the same time. If what you need to dose to maintain your desired level is small, say enough to raise .5-1 dkh, you can probably just dose it all at once or better yet, break it up into 2-3 doses a 1/2-1hr apart if you don't want to get a doser. Best after lights out in your situation.

Also I find it a little difficult to decipher your post. "Several weeks of testing have come in right at 7.3" Is this without doing water changes? If that's with water changes, what is it testing at after?

I see that once you raised dkh to 9, it was back to 7.3 the next day. How about the day after? Does it ever drop below 7.3? If not, I'd question your test kit or testing procedures.

 

[homer1475]

You need to find your tank's daily usage of Alk. Do so by testing several consecutive days at the same time. If what you need to dose to maintain your desired level is small, say enough to raise .5-1 dkh, you can probably just dose it all at once or better yet, break it up into 2-3 doses a 1/2-1hr apart if you don't want to get a doser. Best after lights out in your situation.

Also I find it a little difficult to decipher your post. "Several weeks of testing have come in right at 7.3" Is this without doing water changes? If that's with water changes, what is it testing at after?

I see that once you raised dkh to 9, it was back to 7.3 the next day. How about the day after? Does it ever drop below 7.3? If not, I'd question your test kit or testing procedures.

I do weekly 5G water changes in a 29G tank religiously. I have tested a few times after a WC and it comes in at around 8.2(using reef crystals), but at the end of the week(when I do WC's), I'm usually down to 7.3 ish(it does fluctuate some, but its typically around 7.3).

I did test the second day after dosing and it was at 6.8DKH. I will continue to test for the next week every day(I have been testing only once a week before the WC) and see where I end up as a average loss and dose according to that.

I guess my confusion comes from not realizing I would have to add the ALK every day. I do have quite a few LPS corals and only a single SPS(monitpora) all of who have started to grow, so it's possible they are using the ALK that quick. This is my first time dosing anything as my past experience was only FOWLR.

Thanks everyone for your time and help. :thumbsup:

 

[droog]

Depletion by 1-2 dKH in a day is possible/normal, yes. Your corals are probably happy and growing

Daily dosing? I dose 2-part every hour during the photoperiod to keep Alk stable.

As the KH does gown, so too will your coral growth, so the rate of depletion will slow overt time. Its best to keep KH constant - sudden swings can lead to coral deaths. Don't ask me how I know this...

Trying to stabilise Alk at the same level as your new ASW is one strategy (thats what I do in conjunction with weekly water changes). Another is to implement continuous water changes. A third is to use saturated (or super-saturated) Kalkwasser as your source of top-up water.

For a small system like 29G I'd try Kalkwasser first - unless you have a stand that can hide a dosing pump. Once its setup, 2-part dosing is pretty much set and forget. My coral growth went crazy once I got the dosing right.

-droog

 

[homer1475]

I did try kalkwasser in my topoff. My levels started going way up, 490 at its peak before I stopped. ALK did stay constant, but I felt like the CA was getting out of hand and I had quite a bit of precip on my pumps and such.

I already have the dosing pumps setup in my stand and ready to go if I need to, which looks like I do after some more testing first.